Read the Beforeitsnews.com story here. Advertise at Before It's News here.
Profile image
By Alton Parrish (Reporter)
Contributor profile | More stories
Story Views
Now:
Last hour:
Last 24 hours:
Total:

Young, Thin and Hyperactive: That’s What Outlier Galaxies Look Like

% of readers think this story is Fact. Add your two cents.


The more massive, or full of stars, a galaxy is, the faster the stars in it are formed. This seems to be the general rule, which is contradicted, however, by some abnormal cases, for example thin (not massive) galaxies that are hyperactive in their star formation. Until now the phenomenon had been explained by catastrophic external events like galaxies colliding and merging, but a new theory offers an alternative explanation, related to an in situ (internal) process of galaxy evolution. 

The new theory correctly reproduces the behaviour of both normal and abnormal (or outlier) galaxies, and may be further tested by new observations. A study conducted by the International School for Advanced Studies (SISSA) in Trieste, already posted on the astro.ph archive, is soon to be published in The Astrophysical Journal.
Credits: ALMA (ESO/NAOJ/NRAO)/NASA/ESA/J

If we put the galaxies for which we have the relevant data into a graph relating the mass of stars in each galaxy with the star formation rate of that galaxy, most of them would appear as a compact cloud, which could be described by using a simple function. This graph is known as the Galaxy Main Sequence (GMS), a fundamental observational relation for scientists who study galaxies. The picture that emerges is simple: the more massive the galaxy, the faster its star formation process tends to be.

But straightforward as it seems, there’s a problem. There are some exceptions (abnormal or outlier cases) that do not seem to follow the rule. Certain galaxies, in fact, while not containing many stars have very intense rates of star formation. The most accredited hypothesis to explain these abnormal cases invokes collision and merging between two galaxies: these outliers would therefore be nothing but galaxies captured during their collision, a phenomenon that would lead to a sudden, though transient, increase in their star formation rate.

Claudia Mancuso, SISSA researcher and first author of the study together with SISSA professors Andrea Lapi and Luigi Danese, suggested a fascinating alternative explanation: “According to the approach we developed at SISSA and published only a few months ago, collision and merging, while possible, are not so relevant as to be able to account for the formation and evolution of galaxies, including the outliers observed in GMS”, says the scientist. “Our approach offers an in situ explanation based solely on processes internal to the evolving galaxy”.

The role of the central black hole

In particular, the explanation given by Mancuso and colleagues is based on the close relation that exists between star formation and the growth of the central black hole inside massive galaxies. “These two events are simultaneous and inter-related. As the galaxy forms stars and increases its mass in a constant and substantial manner, its black hole grows as well, and does so at an even faster rate”, explains Mancuso. “At a certain point the black hole becomes so big as to develop an ‘energetic wind’, which sweeps away gas and dust from its surrounding environment. Since these are materials that go into forming new stars, the star formation process comes to an abrupt halt”.

Based on this scenario, Mancuso and colleagues formulated a prediction on GMS and demonstrated that their results are in excellent agreement with the observed mean relation, while providing a new interpretation for outliers. “They are simply very young galaxies”, explains Mancuso. “A galaxy at its very early stages of life, full of dust and gas, has a very high star formation rate but at the same time it still contains very few stars because it hasn’t had the time to form them yet, that’s all”.

 A simple and elegant explanation that does not require any external intervention. As evolution proceeds, the scientist goes on, the galaxies move closer and closer to the mean of the GMS, where they will spend most of their lives, before being “turned off” by the black hole’s energetic wind. “That’s why the data cloud is so dense in that part of the diagram”, she adds.

“Clearly, the acid test comes from the observations”, concludes Mancuso. “We checked the age, estimated by observation, of some outliers in the GMS, and indeed they are always very young galaxies”. More than that, further validation could arrive very soon: “Out theory in fact implies that outlier galaxies, which are young and have very high star formation rates, are still rich in gas, and this will allow us to study them in depth by using the ALMA interferometer”.

Contacts and sources:
Sissa Medialab


Source:


Before It’s News® is a community of individuals who report on what’s going on around them, from all around the world.

Anyone can join.
Anyone can contribute.
Anyone can become informed about their world.

"United We Stand" Click Here To Create Your Personal Citizen Journalist Account Today, Be Sure To Invite Your Friends.

Before It’s News® is a community of individuals who report on what’s going on around them, from all around the world. Anyone can join. Anyone can contribute. Anyone can become informed about their world. "United We Stand" Click Here To Create Your Personal Citizen Journalist Account Today, Be Sure To Invite Your Friends.


LION'S MANE PRODUCT


Try Our Lion’s Mane WHOLE MIND Nootropic Blend 60 Capsules


Mushrooms are having a moment. One fabulous fungus in particular, lion’s mane, may help improve memory, depression and anxiety symptoms. They are also an excellent source of nutrients that show promise as a therapy for dementia, and other neurodegenerative diseases. If you’re living with anxiety or depression, you may be curious about all the therapy options out there — including the natural ones.Our Lion’s Mane WHOLE MIND Nootropic Blend has been formulated to utilize the potency of Lion’s mane but also include the benefits of four other Highly Beneficial Mushrooms. Synergistically, they work together to Build your health through improving cognitive function and immunity regardless of your age. Our Nootropic not only improves your Cognitive Function and Activates your Immune System, but it benefits growth of Essential Gut Flora, further enhancing your Vitality.



Our Formula includes: Lion’s Mane Mushrooms which Increase Brain Power through nerve growth, lessen anxiety, reduce depression, and improve concentration. Its an excellent adaptogen, promotes sleep and improves immunity. Shiitake Mushrooms which Fight cancer cells and infectious disease, boost the immune system, promotes brain function, and serves as a source of B vitamins. Maitake Mushrooms which regulate blood sugar levels of diabetics, reduce hypertension and boosts the immune system. Reishi Mushrooms which Fight inflammation, liver disease, fatigue, tumor growth and cancer. They Improve skin disorders and soothes digestive problems, stomach ulcers and leaky gut syndrome. Chaga Mushrooms which have anti-aging effects, boost immune function, improve stamina and athletic performance, even act as a natural aphrodisiac, fighting diabetes and improving liver function. Try Our Lion’s Mane WHOLE MIND Nootropic Blend 60 Capsules Today. Be 100% Satisfied or Receive a Full Money Back Guarantee. Order Yours Today by Following This Link.


Report abuse

    Comments

    Your Comments
    Question   Razz  Sad   Evil  Exclaim  Smile  Redface  Biggrin  Surprised  Eek   Confused   Cool  LOL   Mad   Twisted  Rolleyes   Wink  Idea  Arrow  Neutral  Cry   Mr. Green

    MOST RECENT
    Load more ...

    SignUp

    Login

    Newsletter

    Email this story
    Email this story

    If you really want to ban this commenter, please write down the reason:

    If you really want to disable all recommended stories, click on OK button. After that, you will be redirect to your options page.